Browse > Article
http://dx.doi.org/10.12652/Ksce.2011.31.6D.779

Study for the Homogeneity of Freeway Free-Flow Speed under the State of LOS-A Low Density  

Yoon, Byoung Jo (인천대학교 도시과학대학 도시환경공학부)
Oh, Seung Hwoon (경기대학교 공과대학 도시.교통공학과)
Publication Information
KSCE Journal of Civil and Environmental Engineering Research / v.31, no.6D, 2011 , pp. 779-784 More about this Journal
Abstract
Freeway FFS (Free-Flow Speed) under the state of LOS (Level of Service) A has been regarded as a homogeneous state to all levels of traffic volume. The features of low-density FFS is served as the basic data for a decision on limited maximal speed, accident analysis, simulation modeling etc. A few researches for the macroscopic characteristics of design and operation speed have been reported, and any study for the microscopic features of freeway free-flow speed under the state of low density has not been done. Therefore, the characteristics of low-density FFS according to the level of traffic volume (1-3 veh/30 sec) and daily hour periods (0-5, 6-8, 9-11, 12-19, 20-23) is microscopically analyzed in this study with huge volume and speed data. It was found that speed distributions are changed and show different behaviors under the conditions of traffic volume levels and daily time periods. V85s (85th percentile speed) at early morning and night periods decrease when levels of traffic volume increase, whereas V85s at day time do not show considerable differences. Especially, FFSs of levels of traffic volume at early morning and night periods, despite low density, is analyzed as heterogeneity, but homogeneity at day time.
Keywords
rural freeway; free-flow speed; low-density; microscopic analysis; speed characteristics;
Citations & Related Records
Times Cited By KSCI : 2  (Citation Analysis)
연도 인용수 순위
1 건설교통부(2009) 도로의 구조.시설기준에 관한 규칙 해설 및 지침.
2 김용석, 조원범(2005) 도로 설계속도, 주행속도, 제한속도의 관계 분석 연구, 대한교통학회지, 대한교통학회, 제23권 제7호, pp. 35-42.
3 대한교통학회(2005) 도로용량편람.
4 장현호, 백승걸, 오성호, 김호정(2011) 스마트도로 안전성 향상 효과의 정량화 연구, 한국ITS학회논문지, 한국ITS학회, 제10 권 제4호, pp. 44-54.
5 AASHTO (1994, 2001) A Policy on Geometric design of highway and street.
6 Barnett, J. (1936) Safe friction factors and superelevation design, Proc., Sixteen Annual Meeting, Washington, D.C. HRB.
7 Fred L. Mannering, Walter P. Kilareski et al. (2002) Principles of Highway Engineering and Traffic Analysis, 3re Ed. New York: Wiley.
8 Karen S. Schurr, Patrick T. McCoy, Geza Pesti, and Ryan Huff (2001) Relationship bet. design, operating and posted speeds on horizontal curves on rural two-lane highways in Nebraska.
9 K. Fitzpatrick, P. Carlson, M. Brewer, and M. Wooldridge (2003) Design speed, operating speed, and posted speed limit practices, TRB, Washington, D.C.
10 McLean, J. (1981) Driver speed behaviour and rural road alignment design, Traffic engineering & control, Vol. 22, Printerhall Limited, London, England.
11 R. A. Krammes, K. Fitzpatrick, J. D. Blaschke, and D. B. Fambro (1996) Speed: understanding design, operating, and posted speed, Texas Transportation Inst., College station.
12 TRB (2010) Highway capacity manual.